It is not an EPIRB.Garmin makes the Garmin Inreach Explorer EPIRB
Both EPIRBs and PLBs talk to the geostationary COSPAR satellites and give access to no-cost national search and rescue services.
The Garmin InReach devices talk to the low-earth orbit Iridium satellites and give access to private S&R services, for a subscription fee.
Different systems, different capabilities, different advantages and disadvantages.